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Related papers: Longitudinal spin polarization in a thermal model

200 papers

We present the exact form of the spin polarization vector and the spin density matrix of massive and massless free particles of any spin and helicity at general global equilibrium in a relativistic fluid with non-vanishing thermal…

Nuclear Theory · Physics 2023-06-16 Andrea Palermo , Francesco Becattini

Since its discovery, global polarization of the $\Lambda$ hyperon in heavy-ion collisions has been firmly established and is widely attributed to the large vorticity generated in the rotating quark-gluon plasma. In contrast, nearly fifty…

High Energy Physics - Phenomenology · Physics 2026-03-23 Feng Liu , Zhoudunming Tu

We compute the fermion spin distribution in the vortical fluid created in off-central high-energy heavy-ion collisions. We employ the event-by-event (3+1)D viscous hydrodynamic model. The spin polarization density is proportional to the…

Nuclear Theory · Physics 2018-03-14 Hui Li , Hannah Petersen , Long-Gang Pang , Qun Wang , Xiao-Liang Xia , Xin-Nian Wang

We study the longitudinal polarization of hyperons and anti-hyperons at forward pseudorapidity, $2.5<\eta<4$, in singly polarized $pp$ collisions at RHIC energies by using different parameterizations of the polarized parton densities and…

High Energy Physics - Phenomenology · Physics 2010-04-06 Wei Zhou , Shan-shan Zhou , Qing-hua Xu

We present a systematic study of $\Lambda$ hyperon's polarization observables using event-by-event (3+1)D relativistic hydrodynamics. The effects of initial hot spot size and QGP's specific shear viscosity on the polarization observables…

Nuclear Theory · Physics 2022-07-27 Sahr Alzhrani , Sangwook Ryu , Chun Shen

We present a framework for spin dynamics in the quark-gluon plasma created in relativistic heavy-ion collisions. Under the approximation of small polarization, macroscopic spin degrees of freedom decouple from the background, and their…

High Energy Physics - Phenomenology · Physics 2025-11-13 Sapna , Sushant K. Singh , David Wagner

Space-time evolution of spin polarization within the framework of hydrodynamics with spin based on de Groot - van Leeuwen - van Weert forms of energy-momentum and spin tensors is studied. Due to the non-boost invariant flow in the system…

High Energy Physics - Phenomenology · Physics 2022-03-10 Wojciech Florkowski , Radoslaw Ryblewski , Rajeev Singh , Gabriel Sophys

The polarization of the $\Lambda$ hyperon has become an important probe of the Quark-Gluon Plasma produced in relativistic heavy-ion collisions. Recently, it has been found that polarization receives a substantial contribution from a local…

The vorticity is a quantity defined in a relativistic fluid that describes how much a fluid element is rotating and accelerating. By measuring the spin polarization of hadrons, it was found that the quark gluon plasma produced in heavy-ion…

Nuclear Theory · Physics 2024-05-17 M. Buzzegoli

We investigate spin polarization dynamics in relativistic heavy-ion collisions using ideal relativistic spin hydrodynamics, employing non-boost-invariant longitudinal solutions as the hydrodynamic background. Operating in the…

Nuclear Theory · Physics 2026-05-12 Matteo Buzzegoli , Aleksandar Gecic , Rajeev Singh

We calculate the contribution to the polarization of $\Lambda$ hyperons in relativistic nuclear collisions at high energy from the decays of $\Sigma^*(1385)$ and $\Sigma^0$, which are the predominant sources of $\Lambda$ production besides…

Nuclear Theory · Physics 2019-10-02 F. Becattini , Gaoqing Cao , Enrico Speranza

The physics interpretation of the recent measurements of the spin polarization of $\Lambda$ hyperons produced in relativistic heavy-ion collisions is discussed. We suggest that the polarization measured in the $\Lambda$ rest frame should be…

High Energy Physics - Phenomenology · Physics 2022-09-07 Wojciech Florkowski , Radoslaw Ryblewski

The hot and dense matter formed in relativistic heavy-ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) is termed quark-gluon plasma (QGP). The evolution of the medium is characterized by non-trivial…

High Energy Physics - Experiment · Physics 2022-09-09 Debojit Sarkar

The longstanding problem of explaining the observed polarization of Lambda hyperons inclusively produced in the high energy collisions of unpolarized hadrons is tackled by considering spin and k_T dependent quark fragmentation functions.…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Anselmino , D. Boer , U. D'Alesio , F. Murgia

We point out that measuring longitudinal polarizations of different hyperons produced in lepton induced reactions are ideal to study the spin transfer of the fragtmenting quark to produced hadron in high energy hadronization processes. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zuo-tang Liang , Chun-xiu Liu

The findings on the spin polarization of $\Lambda$, $\Xi$, and $\Omega$ hyperons and spin alignment of $K^{*0}$, $\phi$, and $D^{*+}$ mesons in relativistic heavy-ion collision experiments at the RHIC and LHC facilities propose the…

High Energy Physics - Phenomenology · Physics 2026-02-17 Bhagyarathi Sahoo , Captain R. Singh , Raghunath Sahoo

Using the AMPT + MUSIC+UrQMD hybrid model, we study the global and local spin polarizations of $\Lambda$ hyperons as functions of the freeze-out temperature of the spin degree of freedom in the hadronic phase of Au+Au collisions at…

Nuclear Theory · Physics 2022-04-06 Yifeng Sun , Zhen Zhang , Che Ming Ko , Wenbin Zhao

We investigate the spacetime evolution of spin polarization within a hydrodynamic framework based on the de Groot--van Leeuwen--van Weert expressions for energy-momentum and spin tensors. The system's deviation from boost invariance results…

High Energy Physics - Phenomenology · Physics 2025-02-18 Wojciech Florkowski , Radoslaw Ryblewski , Rajeev Singh

We calculate the Lambda polarization in an exact analytical, rotating model based on parameters extracted from a high resolution (3+1)D Particle-in-Cell Relativistic hydrodynamics calculation. The polarization is attributed to effects from…

Nuclear Theory · Physics 2015-12-09 Yilong Xie , Robert C. Glastad , Laszlo P. Csernai

We show that spin polarization of a fermion in a relativistic fluid at local thermodynamic equilibrium can be generated by the symmetric derivative of the four-temperature vector, defined as thermal shear. As a consequence, besides…

Nuclear Theory · Physics 2021-07-21 F. Becattini , M. Buzzegoli , A. Palermo